1. Technical Field
The disclosed subject matter is directed towards a process for producing nanoparticles using palladium salt and uses of these nanoparticles.
2. Background Art
Catalysis based on cerium oxide is used as an effective oxidation system in several environmental applications. Cerium oxide was introduced into the catalysis field in 1976, and not initially as a catalyst. Rather, it was chosen as the key oxygen storage component of the three-way catalyst used in automotive exhausts.
Accordingly, cerium oxide is used to extend the air/fuel ratio in the exhaust gas, releasing or accepting oxygen, respectively, under fuel-rich or fuel-lean conditions. This ensures that the noble metal catalyst operates at the desirable stoichiometric air/fuel ratio, at which it effectively converts all three gaseous pollutants (CO, hydrocarbons (HC), and NO) to innocuous products. A solid solution of cerium and zirconium oxides is used in today's catalytic converters as a material with higher oxygen storage capacity than pure ceria. In the years that followed the introduction of ceria into the catalytic converter, many additional merits of cerium oxide were realized, initially as an active catalytic component of the three-way catalyst, and subsequently as a catalyst and sorbent in various industrial applications.
Ceria has been found to be superior to alumina as a noble metal (NM) support, drastically improving the low-temperature activity of the NM for CO oxidation, NO reduction, and the water-gas shift reaction. The enhanced activity of these catalysts has been attributed to a synergistic redox reaction mechanism. Metal-modified cerium oxide has a higher oxygen storage capacity and reducibility than pure ceria. Here, oxygen species, oxygen vacancies, and their mobilities can be greatly modified by added metal species.
Among the precious metals used in the catalytic converter (Pt, Rh, and Pd), palladium is the most cost effective metal of the three. Any improvement in the usage of Pd will improve the cost-base of the present three-way catalyst and possibly diesel engine exhaust clean-up systems.